New Study Says Ancient Humans Hunted Big Mammals To Extinction

https://www.npr.org/sections/thetwo-way/2018/04/19/604031141/new-study-says-ancient-humans-hunted-big-mammals-to-extinction

Excerpt: "11,000 years ago, the average mass of a non-human mammal in North America was about 200 pounds. Now it's about 15 pounds. And the researchers say they're getting even smaller."